Electron guiding and receiving element

Abstract

The invention relates to an electron antenna as an anode for a micro- or nano-focus X-ray generation comprising an antenna base and an antenna element arranged on the antenna base such that the antenna element protrudes from a front surface of the antenna base, wherein the antenna is arranged to guide and attract the electrons in its vicinity to the top the antenna element.

What is claimed is: 
     
       1. Anode for an X-ray tube, characterized in that the anode comprises an electron antenna comprising an antenna element X-ray emitter; wherein the antenna element is arranged on an antenna base; the electron antenna is configured in the same spatial relation to a cathode cup as in a stationary anode X-ray tube or rotating anode X-ray tube, wherein an upper part of the antenna element protrudes out of and parallel to a front surface of the antenna base, wherein the protrusion of the antenna element and an aspect ratio of the antenna element cause a local enhancement of an electric field at a top end of the antenna element,
 wherein a height h of protrusion of the antenna element is between 1 μm-5 mm from the antenna base and a top surface of the antenna element has an anode angle θ of 5°-45°. 
 
     
     
       2. The anode of  claim 1 , wherein the electron antenna comprises an antenna element in the shape of a blade, wherein the shape of the top surface of the blade is a cross, a square, a rectangle, linear segments, an elliptical disc or a circular disc. 
     
     
       3. The anode of  claim 2 , wherein a width t of the blade or of longitudinal sections of the cross, a long side of the rectangle, a side of the square or linear segments shape is between 10 nm-200 μm. 
     
     
       4. The anode of  claim 2 , wherein the circular disc comprises a radius R≤200 μm or where the elliptical disc has a semi-major axis r≤200 μm. 
     
     
       5. The anode of  claim 1 , wherein the electron antenna works as replacement of an anode in vacuum tubes for generating single or multiple micro- or nano-focus X-ray beam; wherein the antenna element is metallic and comprises one or more of the metals: W, Rh, Mo, Cu, Co, Fe, Cr and Sc; or one or more of the alloys: W—Re, W—Mo, Mo—Fe, Cr—Co, Fe—Ag and Co—Cu—Fe. 
     
     
       6. The anode of  claim 1 , wherein the antenna base comprises electrically conductive the material which is one or more of: Cu and Mo. 
     
     
       7. The anode of  claim 1 , wherein the antenna base comprises an electrically insulating material and wherein a plurality of antenna elements are arranged on the antenna base. 
     
     
       8. The anode of  claim 7 , wherein the electrically insulating material is one or more of: BN, Al 2 O 3 . 
     
     
       9. An X-ray generating device comprising the anode of  claim 1 . 
     
     
       10. The X-ray generating device of  claim 9 , wherein said X-ray generating device is a single hot cathode micro- or nano-focus tube by using a hot filament cathode. 
     
     
       11. The X-ray generating device of  claim 10  comprising the said anode can be configured to a single field emission cathode micro- or nano-focus tube by using a field emission cathode. 
     
     
       12. The X-ray generating device of  claim 11 , wherein the field emission cathode can be further configured to allow for thermally assisted emission, such as Schottky emission. 
     
     
       13. The X-ray generating device of  claim 10 , wherein the X-ray generating device is a rotating anode micro- or nano-focus tube, wherein a plurality of antenna elements are radially embedded in a rotating antenna base disc. 
     
     
       14. The X-ray generating device of  claim 9 , wherein said X-ray generating device is a dual cathode micro- or nano-focus tube by using a cathode assembly holding a field emission cathode and a hot filament cathode. 
     
     
       15. The X-ray generating device of  claim 14 , wherein said X-ray generating device further comprises an electron emitter comprising a gate electrode, thereby making the X-ray generating device a triode field emission micro- or nano-focus tube. 
     
     
       16. The X-ray generating device of  claim 9 , wherein said X-ray generating device is a micro- or nano-focus tube with multiple excitation sources comprising multiple cathodes and anodes. 
     
     
       17. The X-ray generating device of  claim 9 , wherein the X-ray generating device is a rotating anode micro- or nano-focus tube, wherein one or a plurality of antenna elements are concentrically embedded in a rotating antenna base disc. 
     
     
       18. An apparatus comprising an X-ray generating device according to  claim 1 , wherein said apparatus is a computed tomography (CT) scanning apparatus, a C-arm type scanning apparatus, a mini C-arm type scanning apparatus, a geological surveying apparatus, an X-ray diffraction apparatus, X-ray fluorescence spectroscopy, an X-ray non-destructive testing apparatus, phase contrast imaging or in a colour CT scanner. 
     
     
       19. An anode for an X-ray tube, characterized in that the anode comprises an electron antenna comprising an antenna element X-ray emitter; wherein the antenna element is arranged on an antenna base; the electron antenna is configured in the same spatial relation to a cathode cup as in a stationary anode X-ray tube or rotating anode X-ray tube, wherein an upper part of the antenna element protrudes out of and parallel to a front surface of the antenna base, wherein the protrusion of the antenna element and an aspect ratio of the antenna element cause a local enhancement of an electric field at a top end of the antenna element,
 wherein the aspect ratio of a blade, defined as the division of a height h to a width t, is in the range of 10-100. 
 
     
     
       20. An anode for an X-ray tube, characterized in that the anode comprises an electron antenna comprising an antenna element X-ray emitter; wherein the antenna element is arranged on an antenna base; the electron antenna is configured in the same spatial relation to a cathode cup as in a stationary anode X-ray tube or rotating anode X-ray tube, wherein an upper part of the antenna element protrudes out of and parallel to a front surface of the antenna base, wherein the protrusion of the antenna element and an aspect ratio of the antenna element cause a local enhancement of an electric field at a top end of the antenna element,
 wherein a metallic antenna element is a tungsten blade and the antenna base comprises two half cylindrical copper parts, wherein the tungsten blade is sandwiched in between the two half cylindrical copper pieces in such a way that a first blade edge of the tungsten blade is protruding from a front surface of the copper cylinder.